The fundamental properties of 2D arrays of magnetic nanowires and nanotubes (NWs and NTs) have been well described theoretically, but real systems are subject to certain flaws and imperfections which strongly affect the mechanism and dynamics of magnetization reversal. Therefore, before exploiting the vast potential of magnetic NWs and NTs, there is a need to investigate the materials parameters as well as the field dependent magnetic properties in real systems. Amongst the various issues at stake for a comprehensive understanding of these arrays is the influence of long-range dipolar interactions because these interactions strongly influence the magnetization reversal and thus the switching field distributions (SFD) which plays a significant role for information storage. Particularly, the width of the SFD is important since smaller values of this parameter leads to less recording errors and it is also a measure of the quality of the recording media. Consequently, the understanding and evaluation of the distinct parameters influencing the interactions and the intrinsic SFD in the magnetization reversal process of such arrays is critical for the development of magnetic recording media. It is shown that the intrinsic SFD mostly originates from nonuniformities of the geometrical parameters such as the aspect ratio and the shape of the magnetic nanostructures. This chapter provides an overview of the MFMcharacterization studies undertaken to understand the reversal behavior of 2D arrays of magnetic NWs and NTs at the nanoscale and the motivations to investigate isolated single domain NWs and NTs.